1. Field of the Invention
The invention relates to a vehicular door.
2. Description of the Related Art
Japanese Patent Application Publication No. JP-A-2000-127880 describes a vehicular door, in which a side impact beam is provided to protect an occupant in a host vehicle from another vehicle when the host vehicle has a lateral collision with the other vehicle. When the host vehicle has a lateral collision with the other vehicle, the side impact beam transmits a collision load applied to the host vehicle, to a vehicle framework such as pillars, thereby absorbing and dispersing the energy applied to the host vehicle at the time of a lateral collision. In general, the side impact beam includes a cylindrical pipe, and brackets. The pipe extends in a vehicle fore-and-aft direction. The brackets are provided at the respective ends of the pipe, and connected to the vehicular door. Japanese Patent Application Publication No. JP-A-2000-94963 describes a side impact beam in which the length of the bracket portion is equal to or longer than substantially half of the entire length of the pipe.
However, because the both ends of the side impact beam support the collision load at the time of a lateral collision, there is a possibility that a bending moment may occur in the side impact beam, and the side impact beam may bend. If the side impact beam bends, the collision load that can be supported extremely decreases. The side impact beam may be reinforced to suppress the bending of the side impact beam. However, it is difficult to reinforce the side impact beam without interfering with the upward and downward movement of door glass.
Japanese Utility Model Application Publication No. JP-U-6-50926 describes a vehicular door that includes a side impact beam, and a reinforcement member (guard means) that is provided below the side impact beam to reduce an impact applied to the lumbar part of an occupant.
The height of a bumper varies among vehicles. Also, even in one vehicle, the height of the bumper varies depending on the number of occupants and the load applied to the vehicle. If the height of the bumper of the other vehicle that collides with the lateral portion of the host vehicle differs from the height of the side impact beam of the host vehicle, serious local deformation occurs in the vehicular door. In Japanese Utility Model Application Publication No. JP-U-6-50926, the reinforcement member is provided to suppress the local deformation of the vehicular door due to a lateral collision, regardless of the height of the bumper of the other vehicle. In this case, however, the size of the reinforcement member is inevitably increased. This increases the weight of the vehicular door.